From one aspect, the present invention relates to a lock comprising a plurality of magnetic elements and members defining respective paths along which the magnetic elements can move between respective releasing positions and locking positions, the magnetic elements obstructing operation of the lock when in their locking positions but not when in their releasing positions.
A lock of the kind preferred in our published British Patent Specification No. 1,572,091. The lock described in this published specification has three magnetic elements, each confined to a respective arcuate path with these paths being spaced apart along an axis of the lock. The lock provides a high degree of security under most circumstances, since the magnetic elements are urged by gravity away from their releasing positions and access to the magnetic elements by picking instruments inserted into a key-hole of the lock is prevented.
If the lock described in the aforesaid published specification is mounted with its axis vertical or can be oriented so that its axis is vertical, the paths to which the magnetic elements are confined will each be horizontal and the magnetic elements will not be biased to any particular position along these paths by gravity. In these circumstances, the lock is less secure than in other circumstances.